ABSTRACT
Since about the late 1960s, most of the Sahel zone of Africa has experienced a fairly severe and prolonged drought (Farmer, 1989). Whether or not this represents a 'permanent' change of climate in the region, or whether rainfall patterns will continue to show periodic fluctuations and soon return to the relatively wet conditions more characteristic of the 1950s and 1960s, is much debated (see, for example, Quinlan, 1986). What is certain is that the change in climate has brought about regional ecological change, and this has had repercussions for economy and society in this region, where agriculture, fishing and livestock production are the main livelihood concerns (Farmer, 1989; Ellis and Galvin, 1994; Todorov, 1985).
